Technical Field
The present disclosure relates to a load current control apparatus adapted to control an electric current flowing through a load device.
Background Art
In supplying electric power from a power supply unit to a load device, if a short fault or the like occurs, for example, on a load device or a power supply line, an excessive current significantly over rating might flow in the power supply unit or load device. To prevent such an overcurrent, a load current control apparatus adapted to control an electric current flowing through a load device is publicly known.
However, in a load device, an electric current larger than an electric current flowing steadily may flow temporarily for a short period of time. Therefore, for example, if a current threshold is set to detect an overcurrent based on the electric current flowing steadily on the load device, each time a larger electric current flows temporarily for a short period of time, a false detection of an overcurrent will occur. On the other hand, if a current threshold is set to detect an overcurrent based on the larger electric current flowing temporarily for a short period of time, there is fear that when a short fault or the like occurs, the overcurrent which primarily should be detected will not be detected or detection of the overcurrent will be delayed.
As an example of conventional techniques intended to solve the above problem, a switching circuit provided with an overcurrent detection function is publicly known, where by setting an overcurrent criterion beforehand, for example, according to electric characteristics of a specific load device (electric characteristics of a lumped load), the switching circuit changes control of a semiconductor switching element adapted to turn on and off a power supply line when the overcurrent criterion is met (see, for example, Patent Document 1). Also as another example of the conventional techniques, a load current control apparatus is publicly known, where in relation to, for example, a load device (lumped load) for which it is predictable when an electric current larger than an electric current flowing steadily flows, the load current control apparatus avoids detecting an overcurrent by masking an overcurrent detection signal just when an electric current larger than the electric current flowing steadily flows (see, for example, Patent Document 2).